1. Field of the Invention
The present invention relates to an electric nailing gun, and more particularly, to an electric nailing gun that automatically reduces the impact of a plunger while no nail is inside.
2. Description of the Related Art
When using a conventional electric nailing gun and no nail is inside the nail magazine, actuating the electrically-controlled switch still causes the plunger to move continuously. Striking the plunger when the nail magazine is empty causes the plunger to impact the structure of the gun body around the bore. Therefore, the plunger and the structure of the gun body around the bore wear quickly as the electric nailing gun is operated for a period of time. Some of conventional electric nailing guns are installed with elastic cushion means, such as a rubber cushion, around the bore of the gun body for buffering the impact of the plunger when the plunger runs idle. Due to high striking frequency and high impact force of the plunger, the service life of such rubber cushion is very short. In addition, the rubber cushion will become degenerate, like hardened, within a short time to be of no buffer. Therefore, in some countries, like USA, there is a related safety code requiring that an electric nailing gun has to pass the impact test of a long period and many times while no nail is inside the gun. This impact test is a great challenge to electric nailing gun manufacturers who are trying to develop electric nailing guns having more powerful impact.
In view of the aforesaid problem, an electric nailing gun with a nail sensor is developed. The nail sensor is mounted at the top of the nail magazine to detect whether the presence of the magazine follower is in a predetermined position. The magazine follower reaches such a predetermined position when the nail magazine is empty. At the same time, the nail sensor stops the electric nailing gun from working. However, because the nails are not mechanically precise to have relatively greater tolerance allowed while being manufactured, and the nails and the nail magazine also have their manufacturing tolerance, the sensor may misjudge to stop the electric nailing gun from working when the nails are still left in the nail magazine or to have the electric nailing gun keep working when the nail magazine is empty.
Therefore, it is desirable to provide an electric nailing gun that eliminates the aforesaid drawbacks.